The present invention relates to a filter element, particularly a secondary element for a filter system in the intake tract of an internal combustion engine, comprising a zig-zag pleated filter medium, which is surrounded by a circumferential frame of polyurethane foam.
German patent no. DE 12 99 534 discloses a filter insert made of a folded filter material. This filter insert is provided with an adhesive mass, which is bonded to the filter material and extends transversely of the fold edges. This adhesive is used as a spacer.
Conventional filters of this type for motor vehicle engines also use an adhesive mass or adhesive beads as spacers. Such adhesive beads are at the same time applied continuously along the sides of the filter material during manufacture. In zig-zag pleated filter materials, these adhesive beads serve as a lateral seal of the filter insert.
With continued advances in automotive engineering and the development toward compact vehicles, less and less space is available for a filter system in the engine compartment of a motor vehicle. The space is often insufficient for a conventional rectangular cartridge, so that two filters or two filter systems are sometimes placed in different locations.